Not Applicable.
Not Applicable
1. Field of Invention
This invention relates to computers and computer keyboards, and specifically to methods for disabling keyboard operations.
2. Description of Prior Art
The ability to disable the operation of the keys of a computer keyboard would be appreciated by any computer user who owns a cat or has small children, both of which could cause unwelcome entries into the computer should they inadvertently depress keyboard keys while the operator momentarily stepped away. Additionally, it would be useful to disable the keyboard key operation when one wished to clean the keyboard or place a large book on the desk with the possibility that the book would again inadvertently depress keyboard keys.
Unplugging the cable between the keyboard and computer is cumbersome, and in any case can cause the computer""s operating system to declare a fault condition. Mechanical means have been proposed for locking keyboard keysxe2x80x94for example, U.S. Pat. Nos. 3,703,987 and 3,906,814 both describe mechanical means to lock the operation of keyboard keys. However, both of these methods would be difficult to apply simultaneously to all one hundred or more keys of a typical computer keyboard, and also are not appropriate for the membrane or Hall effect keying means used in most popular computer keyboards.
Some computer operating systems, e.g., Microsoft""s NT, allow the user to log off, rendering the computer unusable until the user logs back on using a special password. Although this would effectively achieve the goal of disabling the computer keyboard, it has several distinct disadvantages: 1) not all operating systems accommodate this, 2) logging off and logging back on require a number of user steps that would be inconvenient when stepping away for only few moments, 3) the keyboard is not truly disabled and depressed keys are still recognized by the computer""s operating system, thus since most logon systems allow only a limited amount of tries, random depressing of keyboard keys when logged off could potentially result in the operating system observing multiple, unsuccessful logon attempts which would cause the operating system to retreat to a secure condition, causing the user difficulty in re-enabling the computer.
A software-based method is described in U.S. Pat. No. 4,827,440 which includes keyboard lock-out means that is implemented via the computer""s CPU directly. This method involves operating system-level software routines that filter selected keys from being passed on to the computer""s CPU. The method described in this patent is targeted for a more long-term application use of the computer and has several disadvantages with regard to the goals of the present invention: 1) programming and activating the method described in U.S. Pat. No. 4,827,440 involves many steps which would be overly burdensome to a user who wishes to de-activate the computer for only a few minutes; indeed, activation of the lockout processes as described in the patent would likely require resetting the computerxe2x80x94clearly counter to the more casual xe2x80x9con the flyxe2x80x9d goal of the current invention, 2) since the method of U.S. Pat. No. 4,827,440 involves software routines embedded at the operating system level, it would be difficult or impossible to incorporate into a user""s existing computer system, 3) as described in U.S. Pat. No. 4,827,440, some keys cannot be locked out at all.
An all-electronic method independent of the computer CPU would serve the purpose better. U.S. Pat. No. 6,056,193 describes an integral encoded device reader, such as a card reader, which can be used to validate and enable keyboard-based operations. Such a mechanism could be extended to include all keyboard operation, thus achieving the desired goal of de-activating the keyboard, however, such a method adds considerable cost to the keyboard, is not compatible with the significant manufacturing investment in commonly accepted keyboard form-factors, and adds inconvenience to the computer user who would now need to keep track of an additional piece of computer hardware, e.g., a magnetically encoded plastic card.
What is needed is a simple, inexpensive means to disable computer keyboards that is easily compatible with current manufactured keyboard forms.
Therefore, in accordance with the present invention a method for temporarily disabling the operation of a computer keyboard uses the simultaneous depression of a multiple of existing keyboard keys to effect the disabling. Alternatively, a disabling mechanism can be placed in a keyboard extension cable, thus allowing introduction of the inventive feature to current keyboards. The inventive method recognizes the multiple, simultaneous depression of keyboard keys and inhibits further communication of depressed keys to the computer, thus effectively disabling the keyboard. An additional depression of a multiple of keyboard keys then re-enables keyboard operation.
Accordingly, several objects and advantages of the present invention are:
a) to provide a method for disabling a computer keyboard that is inexpensive,
b) to provide a keyboard disabling method that is simple to use,
c) to provide a keyboard disabling method that is compatible with existing keyboard manufacturing forms,
d) to provide an alternate keyboard disabling method that is compatible with, and requires no modifications of, existing keyboards.